Clang treats function-like macros "correctly", in that, per the C11 spec:
"Each subsequent instance of the function-like macro name followed by a (
[...] is replaced by the replacement list [...]".
Additionally, fprintf is also permitted to be defined as a function-like
macro rather than as a true function: "Any function declared in a header
may be additionally implemented as a function-like macro defined in the
header [...]". The specification then suggests surrounding the name of the
function in parens to avoid this, which is the technique we use here to avoid
the function-like macro being invoked.
The other fix here is to use uintptr_t for some arithmetic, since Git
is expecting an int as the value here and not a pointer.
